Publications by authors named "Nanyang Yu"

22 Publications

  • Page 1 of 1

Exposure to legacy and novel perfluoroalkyl substance disturbs the metabolic homeostasis in pregnant women and fetuses: A metabolome-wide association study.

Environ Int 2021 May 13;156:106627. Epub 2021 May 13.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China.

Background: Perfluoroalkyl substances (PFASs) exist extensively and several of these have been verified to be toxic. Prenatal exposure to PFASs has attracted much attention. Metabolome-wide association analyses can be used to explore the toxicity mechanisms of PFASs by identifying associated biomarkers.

Objectives: To evaluate associations between the metabolites in maternal and cord serum and internal exposure to several common PFASs.

Methods: Paired maternal and cord serum samples were collected from 84 pregnant women who gave birth between 2015 and 2016. Seven legacy and two novel PFASs were measured. A nontarget metabolomic method and an iterative metabolite annotation based on metabolic pathways were applied to characterize the metabolic profiles. Linear regression adjusted with the false discovery rate and covariates was used to indicate the associations.

Results: A total of 279 features in maternal serum and 338 features in cord serum were identified as metabolites associated with PFAS exposure. Perfluorooctanoic acid (PFOA) and perfluorohexane sulfonic acid (PFHxS) were two PFASs associated with more metabolites, while the two novel chlorinated polyfluorinated ether sulfonic acids (Cl-PFESAs) showed less relevance to the metabolome. With pathway enrichment analysis, we found that three fatty acid metabolisms and retinol metabolism were correlated with PFAS exposure in maternal blood, and that sterol metabolism showed the correlation in both maternal serum and cord serum.

Conclusions: We identified metabolites and pathways in pregnant women and fetuses associated with the exposure to several PFAS, indicating a promising application for metabolome-wide association studies. Additional research is needed to confirm causation.
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http://dx.doi.org/10.1016/j.envint.2021.106627DOI Listing
May 2021

Response to Comment on "Suspect and Nontarget Screening of Per- and Polyfluoroalkyl Substances in Wastewater from a Fluorochemical Manufacturing Park".

Environ Sci Technol 2021 04 30;55(8):5593-5596. Epub 2021 Mar 30.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China.

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http://dx.doi.org/10.1021/acs.est.1c01254DOI Listing
April 2021

Screening priority indicator pollutants in full-scale wastewater treatment plants by non-target analysis.

J Hazard Mater 2021 07 23;414:125490. Epub 2021 Feb 23.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, 210023 Jiangsu, PR China. Electronic address:

Wastewater treatment plants (WWTPs) are the main sources of emerging contaminants (ECs) in aquatic environment. However, the standards for limiting emerging pollutants in effluent are extremely lacking. We investigated the occurrence and removal of emerging pollutants in 16 WWTPs in China using non-target analysis. 568 substances screened out were divided into 9 kinds including 167 pharmaceuticals, 113 natural substances, 85 pesticides, 86 endogenous substances, 64 chemical raw materials, 14 personal care products, 17 food additives, 6 hormones and 16 others. And they were divided into 5 fates. Pesticides and pharmaceutical compounds seemed to be the most notable categories, the kinds detected in each sample is the largest compared with other compounds. Besides, the average removal rate of pesticides and pharmaceuticals in all WWTPs were the lowest, at 9.54% and 23.77%, respectively. Priority pollutants were screened by considering distribution of pollutants with different fates. Pollutants with the same fate especially "consistent" in different WWTPs had attracted attention. 4 potential priority pollutants including metoprolol, carbamazepine, 10, 11-dihydro-10, 11-dihydroxycarbamazepine and irbesartan were proposed. And it was found that the 4 compounds, "consistent suspects" and "consistent non-targets" had similar rankings of removal rate in 16 WWTPs, which can reflect the performance of different WWTPs.
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http://dx.doi.org/10.1016/j.jhazmat.2021.125490DOI Listing
July 2021

Non-target and suspect screening of per- and polyfluoroalkyl substances in Chinese municipal wastewater treatment plants.

Water Res 2020 Sep 19;183:115989. Epub 2020 Jun 19.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China. Electronic address:

Wastewater treatment plant (WWTP) is one of the major sources of per- and polyfluoroalkyl substances (PFASs) to the aquatic environment. In this study, wastewater samples were collected from 17 WWTPs in 17 cities of China to investigate emerging PFASs in WWTPs. To comprehensively identify PFASs in the wastewater samples, an integrated suspect screening, homologue-based and fragment-based non-target screening method is proposed. Sixty-three PFASs from 13 classes (25 subclasses) were identified, including 14 legacy and 49 emerging PFASs, and this study is the first to report on 12 of these PFASs. We found that emerging PFASs concentration had a significantly positive correlation with the gross domestic product, indicating more substitution of legacy PFASs in the developed area of China. We also analyzed the removal of the 13 PFAS classes, and found that all discovered PFAS classes were not completely removed after the treatment process, whereas the class of perfluoroalkyl ether alcohols significantly increased. All of these results imply that the release of emerging or unknown PFASs from WWTPs is a universal but not negligible problem in China.
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http://dx.doi.org/10.1016/j.watres.2020.115989DOI Listing
September 2020

Suspect screening and risk assessment of pollutants in the wastewater from a chemical industry park in China.

Environ Pollut 2020 Aug 2;263(Pt B):114493. Epub 2020 Apr 2.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210046, People's Republic of China. Electronic address:

Owing to the production and use of chemicals in chemical industry parks (CIPs), these areas are considered to be highly polluted. However, the type of pollutants presents in the wastewater from CIPs and the risk posed to the environment due to the release of these pollutants remains unclear. In this study, suspect screening was combined with traceability analysis to determine the type of pollutants present in wastewaters at 9 chemical enterprises and wastewater treatment plants (WWTPs) in the CIPs. Additionally, the distribution of nine pollutants from the WWTPs' effluent stage and the risk they posed to the surrounding river was examined through target analysis. Upon conducting suspect analysis, the presence of 65 and 64 chemicals in the 9 chemical enterprises' wastewaters and WWTPs, respectively, was tentatively identified. Traceability analysis of the compounds screened in the effluent from the WWTPs determined that 41 substances were identified as characteristic pollutants of the chemical enterprises, indicating that the suspect screening strategy enabled relatively more efficient identification of the characteristic pollutants compared to traditional quantitative analysis. Targeting analysis combined with ecological risk assessment showed that metolachlor, carbendazim, atrazine, diuron, and chlorpyrifos posed relatively higher risks to aquatic organisms in the surrounding river. Therefore, the refined management of the wastewater treatment plant in the CIPs is necessary.
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http://dx.doi.org/10.1016/j.envpol.2020.114493DOI Listing
August 2020

Metabolomic insights into the lasting impacts of early-life exposure to BDE-47 in mice.

Environ Pollut 2020 Aug 4;263(Pt B):114524. Epub 2020 Apr 4.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China. Electronic address:

Early-life exposure to toxicants may have lasting effects that adversely impact later development. Thus, although the production and use of a toxicant have been banned, the risk to previously exposed individuals may continue. BDE-47, a component of commercial penta-BDEs, is a persistent organic pollutant with demonstrated neurotoxicity. To investigate the persistent effects of BDE-47 and the mechanisms thereof, we employed a metabolomics approach to analyze the brain, blood and urine of mice exposed to BDE-47 for 28 days and then 3 months post-exposure. In the brain, BDE-47 was detectable just after exposure but was below the limit of detection (LOD) 3 months later. However, the metabolomic alterations caused by early-life exposure to BDE-47 persisted. Potential biomarkers related to these alterations included phosphatidylcholine, lysophosphatidylcholine, sphingomyelin and several amino acids and biogenic amines. The metabolic pathways involved in the response to BDE-47 in the brain were mainly those related to glycerophospholipid metabolism, sphingomyelin metabolism and neurotransmitter regulation. Thus, our study demonstrates the utility of metabolomics, as the omics most closely reflecting the phenotype, in exploring the mechanisms underlying the lasting effects induced by early-life BDE-47 exposure.
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http://dx.doi.org/10.1016/j.envpol.2020.114524DOI Listing
August 2020

Nontarget Discovery of Per- and Polyfluoroalkyl Substances in Atmospheric Particulate Matter and Gaseous Phase Using Cryogenic Air Sampler.

Environ Sci Technol 2020 03 6;54(6):3103-3113. Epub 2020 Mar 6.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China.

Novel per- and polyfluoroalkyl substances (PFASs) have become a key issue in global environmental studies. Although several novel PFASs have been discovered in atmospheric particulate matter through nontarget analysis, information on the environmental occurrence of novel PFASs in atmospheric gaseous phases and conventional sampling techniques is somewhat deficient. Therefore, this Article describes a new type of air sampler, the cryogenic air sampler (CAS), which was used to collect all atmospheric components simultaneously. Nontarget analysis then was performed through PFASs homologue analysis. A total of 117 PFAS homologues (38 classes) were discovered, 48 of which (13 classes) were identified with confidence Level 4 or above. Eleven chlorinated perfluoropolyether alcohols (3 classes) and four chlorinated perfluoropolyether carboxylic acids (2 classes) have been reported for the first time in this Article. This Article is also the first report of 12 hydrosubstituted perfluoroalkyl carboxylates (H-PFCAs) in the atmosphere. H-PFCAs and chlorinated perfluoropolyether carboxylic acids were mainly distributed in the particular phase. These results are evidence that novel chlorinated polyether PFASs should be the focus of future study.
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http://dx.doi.org/10.1021/acs.est.9b05457DOI Listing
March 2020

Suspect and non-target screening of pesticides and pharmaceuticals transformation products in wastewater using QTOF-MS.

Environ Int 2020 04 25;137:105599. Epub 2020 Feb 25.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China. Electronic address:

Pesticides and pharmaceuticals are widely used in modern life and are discharged into wastewater after usage. However, a large number of transformation products (TPs) are formed through abiotic (hydrolysis/photolysis, etc.) and biotic (aerobic/anaerobic degradation by micro-organisms) wastewater treatment processes, and the structure and potential risk of TPs are still unclear. In this study, a suspect and non-target screening was performed to monitor these chemicals with HPLC-QTOF-MS. We identified 60 parent compounds by suspect screening in three Chinese wastewater treatment plants with the commercial database of pesticides and pharmaceuticals, and they were confirmed by authentic standards. Then, suspect and non-target screening strategies based on the predicted diagnostic fragment ions were used to screen TPs of the 60 parent compounds. We tentatively identified 50 TPs and confirmed thirteen of them with authentic standards. Among 13 quantified TPs, about 40% of them showed higher concentration than their parent compounds in effluent. Especially, cloquintocet, as a TP of cloquintocet-mexyl, had a concentration ratio TP/parent = 14,809 in effluent. Twenty-five TPs had higher predicted toxicity than the corresponding parent compounds by calculating their LC values towards aquatic organisms using toxicity prediction software. Twenty identified TPs were firstly reported in this study. These results indicate the importance of TP analysis in environmental monitoring in wastewater.
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http://dx.doi.org/10.1016/j.envint.2020.105599DOI Listing
April 2020

Transplacental Transfer of Per- and Polyfluoroalkyl Substances Identified in Paired Maternal and Cord Sera Using Suspect and Nontarget Screening.

Environ Sci Technol 2020 03 25;54(6):3407-3416. Epub 2020 Feb 25.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China.

Novel per- and polyfluoroalkyl substances (PFASs) in various environmental media have attracted increasing attention; however, the information regarding PFASs exposure in pregnant women and fetuses is insufficient. In this study, we built and applied suspect and nontarget screening strategies based on the mass difference of the CF, CFO, and CHCF units to select potential novel PFASs from 117 paired maternal and cord sera. In total, 10 legacy PFASs and 19 novel PFASs from 10 classes were identified to be above confidence levels 3, among which 14 were not previously reported in human serum. Novel PFASs accounted for a considerable percentage of total PFASs in pregnant women and can be transferred to fetuses at non-negligible concentrations (i.e., 27.9% and 30.3% of total PFAS intensities in maternal and cord sera, respectively). The transplacental transfer efficiency (TTE) of PFASs showed a U-shape trend in the series of perfluoroalkyl carboxylic acids, perfluoroalkyl sulfonic acids, and unsaturated perfluorinated alcohols. The TTE of novel PFASs is suggested to be structure-dependent, based on a flexible docking experiment. This study provides comprehensive TTE information on legacy and novel PFASs for the first time, and additional toxicity studies are needed to evaluate the risk of novel PFASs further.
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http://dx.doi.org/10.1021/acs.est.9b06505DOI Listing
March 2020

Biomonitoring of organophosphate triesters and diesters in human blood in Jiangsu Province, eastern China: Occurrences, associations, and suspect screening of novel metabolites.

Environ Int 2019 10 29;131:105056. Epub 2019 Jul 29.

School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, China. Electronic address:

Since organophosphate (OP) triesters are ubiquitous in environmental matrices, there is an increasing concern regarding human exposure to OP triesters or their metabolites. In this study, we measured levels of 16 OP triesters and 4 OP diesters in n = 99 human blood samples of non-occupationally exposed adults (aged 18-87) from Jiangsu Province, eastern China. Based on the measured concentrations, statistical difference and correlativity were calculated to characterize the population diversity and potential sources of OP triester and diester. Di (2-ethylhexyl) phosphate (DEHP) and 2-ethylhexyl diphenyl phosphate (EHDPP) were found in many participants' blood, with median concentrations of 1.2 (range: n.d. - 44.7, detection frequency: 99%) and 0.85 (n.d. - 28.8, 68%) ng mL, respectively. Blood samples of older participants contained significantly lower concentrations of OP diesters or triesters than their younger counterparts (p < 0.01). Regional- and age-specific differences in the blood concentrations of OP triesters and diesters were attributed to disparities in environmental exposure intensity. EHDPP and tris (phenyl) phosphate (TPHP), the predominant OP triesters, exhibited significant positive correlation (p < 0.01, r = 0.84) suggestive of analogous transport behavior from similar exposure sources to humans. The increased correlations between diphenyl phosphate (DPHP) and TPHP as well as with EHDPP as observed from the multivariate regression suggests that DPHP could be derived from the metabolism of both TPHP (the crucial precursor) and EHDPP. When the blood samples were subsequently screened using high-resolution spectrometry, we detected five novel OP metabolites: glucuronide conjugates of hydroxylated DEHP (OH-DEHP glucuronide conjugate), 2-ethylhexyl monophenyl phosphate (EHMPP), hydroxylated EHMPP (OH-EHMPP), dihydroxylated bis(2-butoxyethyl) phosphate (di-OH-BBOEP), and dihydroxylated tris(butyl) phosphate (di-OH-TNBP). Overall, this study provides novel information regarding the occurrence of OP triesters and diesters, and further suggested several novel OP metabolites in human blood.
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http://dx.doi.org/10.1016/j.envint.2019.105056DOI Listing
October 2019

Organophosphate Ester, 2-Ethylhexyl Diphenyl Phosphate (EHDPP), Elicits Cytotoxic and Transcriptomic Effects in Chicken Embryonic Hepatocytes and Its Biotransformation Profile Compared to Humans.

Environ Sci Technol 2019 02 1;53(4):2151-2160. Epub 2019 Feb 1.

Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering , Nanjing University of Science and Technology , Nanjing 210094 , People's Republic of China.

The effects of 2-ethylhexyl diphenyl phosphate (EHDPP) on cytotoxicity and mRNA expression, as well as its metabolism, were investigated using a chicken embryonic hepatocyte (CEH) assay. After incubation for 36 h, the lethal concentration 50 (LC) was 50 ± 11 μM, suggesting that EHDPP is one of a small cohort of highly toxic organophosphate esters (OPEs). By use of a ToxChip polymerase chain reaction (PCR) array, we report modulation of 6, 11, or 16/43 genes in CEH following exposure to 0.1, 1, or 10 μM EHDPP, respectively. The altered genes were from all nine biological pathways represented on the ToxChip including bile acids/cholesterol regulation, glucose metabolism, lipid homeostasis, and the thyroid hormone pathway. After incubation for 36 h, 92.5% of EHDPP was transformed, and one of its presumed metabolites, diphenyl phosphate (DPHP), only accounted for 12% of the original EHDPP concentration. Further screening by use of high-resolution mass spectrometry revealed a novel EHDPP metabolite, hydroxylated 2-ethylhexyl monophenyl phosphate (OH-EHMPP), which was also detected in a human blood pool. Additional EHDPP metabolites detected in the human blood pool included EHMPP and DPHP. Overall, this study provided novel information regarding the toxicity of EHDPP and identified a potential EHDPP metabolite, OH-EHMPP, in both avian species and humans.
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http://dx.doi.org/10.1021/acs.est.8b06246DOI Listing
February 2019

Suspect and Nontarget Screening of Per- and Polyfluoroalkyl Substances in Wastewater from a Fluorochemical Manufacturing Park.

Environ Sci Technol 2018 10 24;52(19):11007-11016. Epub 2018 Sep 24.

State Key Laboratory of Pollution Control and Resource Reuse , Nanjing University , Nanjing 210008 , P. R. China.

Although per- and polyfluoroalkyl substances (PFASs) have always been a key issue in the global environmental field, there are still a lot of undiscovered PFASs in the environment due to new PFAS alternatives developed by manufacturers. Wastewater treatment plants (WWTPs), as one of the sources for PFASs, are an important part of the process of releasing new PFASs into the environment. In this study, suspect screening and PFAS homologue analysis with quadrupole time-of-flight tandem mass spectrometry were used to discover PFASs in wastewater from a WWTP near Yangtze River. Fifteen classes with 90 PFASs were identified, including 12 legacy PFASs (2 classes), 41 previously reported PFASs (7 classes), and 37 new PFASs (6 classes), and 18 of these PFASs were also detected in the nearby Yangtze River. Only 1 PFAS class was removed through the treatment processes (fold change < 1/6). Conversely, 4 PFAS classes increased through the treatment processes (fold change > 6), which could be the transformation products of PFAS precursors. These results implied that most discovered PFASs were not effectively removed in the WWTP. Chlorine-substituted perfluoroalkyl carboxylates (Cl-PFCAs) as the main component of wastewater were detected only in downstream, meaning that Cl-PFCAs in downstream possibly originated from the WWTP.
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http://dx.doi.org/10.1021/acs.est.8b03030DOI Listing
October 2018

Non-Target and Suspect Screening of Per- and Polyfluoroalkyl Substances in Airborne Particulate Matter in China.

Environ Sci Technol 2018 08 30;52(15):8205-8214. Epub 2018 Jul 30.

State Key Laboratory of Pollution Control and Resource Reuse , School of the Environment, Nanjing University , Nanjing , People's Republic of China.

Airborne particulate matter (APM) has an important role in inhalation exposure, especially in China. The environmental occurrence of conventional and unknown per- and polyfluoroalkyl substances (PFASs) in APM remains unclear. Therefore, in this study, a two-stage experiment was designed to identify potential PFASs and to investigate their distribution in APM. Indoor and outdoor APM samples were collected from five selected cities in China. Through PFAS homologue analysis and suspect screening, 50 peaks were identified with different confidence levels (levels 1-3). Among the identified PFASs, 34 emerging PFASs including p-perfluorous nonenoxybenzenesulfonate, 6:2 polyfluoroalkyl phosphate diester, n:2 fluorotelomer sulfonates, n:2 fluorinated telomer acids, n:2 chlorinated polyfluoroalkyl ether sulfonic acids, 1:n polyfluoroalkyl ether carboxylic acids (1:n PFECAs), perfluoroalkyl dioic acids (PFdiOAs), hydro-substituted perfluoroalkyl dioic acids (H-PFdiOAs), and unsaturated perfluorinated alcohols (UPFAs) were identified in APM. In particular, 1:n PFECAs, PFdiOAs, H-PFdiOAs, and UPFAs were first detected in APM. Although human exposure to perfluorooctanoic acid via inhaled APM was noted to not be a risk (hazard quotient <0.1) in this study, the expansion of the PFASs screened in APM implies that human exposure to PFASs might be much more serious and should be considered in future risk assessments in China.
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http://dx.doi.org/10.1021/acs.est.8b02492DOI Listing
August 2018

Pharmacokinetics and effects of tetrabromobisphenol a (TBBPA) to early life stages of zebrafish (Danio rerio).

Chemosphere 2018 Jan 29;190:243-252. Epub 2017 Sep 29.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China. Electronic address:

In silico and in vivo approaches were combined in an aggregate exposure pathway (AEP) to assess accumulation and effects of waterborne exposures of early life stages of zebrafish (Danio rerio) to tetrabromobisphenol A (TBBPA). Three metabolites, two of which were isomers, were detected in fish. Two additional metabolites were detected in the exposure solution. Based on kinetics modeling, proportions of TBBPA that were bioaccumulated and metabolized were 19.33% and 8.88%, respectively. Effects of TBBPA and its metabolites were predicted by use of in silico, surflex-Dock simulations that they were capable of interacting with ThRα and activating associated signaling pathways. TBBPA had a greater toxic contribution than its metabolites did when we evaluated the toxicity of these substances based on the toxicity unit method. The half of the internal lethal dose (ILD) was 18.33 μg TBBPA/g at 74 hpf. This finding was further confirmed by changes in expressions of ThRα and other NRs as well as associated genes in their signal pathways. Specifically, exposure to 1.6 × 10, 3.3 × 10 or 6.5 × 10 μg TBBPA/L significantly down-regulated expression of ThRα and associated genes, ncor, c1d, ncoa2, ncoa3, and ncoa4, in the AR pathway and of er2a and er2b genes in the ER pathway.
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http://dx.doi.org/10.1016/j.chemosphere.2017.09.137DOI Listing
January 2018

Extended Virtual Screening Strategies To Link Antiandrogenic Activities and Detected Organic Contaminants in Soils.

Environ Sci Technol 2017 Nov 16;51(21):12528-12536. Epub 2017 Oct 16.

Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan , Saskatoon, Saskatchewan S7N5B3, Canada.

A tiered screening strategy based on extensive virtual fractionation and elucidation was developed to simplify identification of toxicants in complex environments. In tier1-virtual fractionation, multivariate analysis (MVA) was set up as an alternative of physical fractionation. In tier2-virtual structure elucidation, in-house quantitative structure-retention relationship (QSRR) models and toxicity simulation methods were developed to simplify nontarget identification. The efficiency of the tiered virtual strategy was tentatively verified by soil samples from a chemical park contaminated by antiandrogenic substances. Eight out of 18 sites were detected as antiandrogenic, while none of them exhibited androgenic agonist potencies. Sixty-seven peaks were selected for further identification by MVA, among which over 90% were verified in androgenic fractions in traditional effect-directed analysis (EDA). With 579 tentative structures generated by in silico fragmentation, 74% were elucidated by QSRR and 65% were elucidated by in silico toxicity prediction. All prior peaks were identified at different confidence levels with over 40% of the identified peaks above confidence level 2b, which has been increased over 40% with less than half of the time spent compared to traditional EDA. Such a combination of tiered virtual screening methods provides more efficient and rapid identifications of key toxicants at contaminated sites.
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http://dx.doi.org/10.1021/acs.est.7b03324DOI Listing
November 2017

Influence of blooms of phytoplankton on concentrations of hydrophobic organic chemicals in sediments and snails in a hyper-eutrophic, freshwater lake.

Water Res 2017 04 31;113:22-31. Epub 2017 Jan 31.

State Key Laboratory of Pollution Control and Resource Reuse, School of Environment, Nanjing University, Nanjing, People's Republic of China. Electronic address:

Blooms of phytoplankton, which are common in freshwater ecosystems, might not only affect quality of water but also influence biogeochemical processing of pollutants. Based on three years of field observations in sediments of Tai Lake, China, concentrations of organochlorine (OC) pesticides and polycyclic aromatic hydrocarbons (PAHs) in areas where blooms occurred were 2.4 and 3.4 times greater than concentrations in areas without blooms. Concentrations of octylphenol (OP), nonylphenol (NP) and bisphenol A (BPA) in areas where blooms did not occur were 3.8, 4.4 and 2.6 times greater than concentrations in areas where blooms did occur. To explain the differences, simultaneous, seasonally determinations of the water-sediment-phytoplankton-snails disequilibria were determined empirically. Greater sinking and lesser diffusion were shown to be probable drivers of the burial of δ-HCH, 4-ring and 5-ring PAHs in surface sediments of areas in which blooms occurred, being as much as 0.58, 38 and 45 g month. Large biodegradation and low burial was shown to be the probable reason of the inverse proportion of NP, OP and BPA in both water and sediment to biomass which might be due to the enhanced metabolic capacity of bacterial community associated with algae blooms. These phenomena further influence the persistent hydrophobic organic chemicals in the snail species (Bellamya quadrata) being greater in winter but lesser in summer, which is probably due to the positive relationship with the concentrations in sediment when snails were dormant and with the concentrations in water after dormancy. Thus, in Tai Lake, the fate and distribution of persistent and biodegradable contaminants in sediments and snails is influenced by blooms of phytoplankton, which should be included in models of environmental fates of contaminants.
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http://dx.doi.org/10.1016/j.watres.2017.01.059DOI Listing
April 2017

Perfluoroalkyl acids in the water cycle from a freshwater river basin to coastal waters in eastern China.

Chemosphere 2017 Feb 28;168:390-398. Epub 2016 Oct 28.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China.

The distribution of perfluoroalkyl acids (PFAAs), one class of persistent organic pollutants, in groundwater, especially in confined aquifers remains poorly understood. In this study, we investigated the occurrence of 12 PFAAs through a water cycle from the Huai River Basin to the Yellow Sea, including confined aquifers, unconfined aquifers, rivers, and coastal waters. We found the ubiquity of PFAAs in all types of samples, including those from confined aquifers (2.7-6.8 ng/L). Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the major PFAAs in all samples, accounting for an average of 49.1% (0.8-84.8%) and 33.3% (6.3-92.2%) of total PFAAs, respectively. Comparing the concentration of PFOA with that of PFOS, we found a higher concentration of PFOA in rivers and a higher concentration of PFOS in confined aquifers. Short-chain perfluoropentanoic acid accounted for an average of 10.3% (1.9-24.6%) of total PFAAs in rivers and coastal waters. Branched isomers of both PFOA and PFOS were detected in most samples (36/42 and 39/42, respectively). One-way analysis of variance indicated a significant difference in the profiles of PFAAs among the different types of water samples. Principal component analysis suggested that rainwater and recent uses of PFAAs could be the major sources of PFAAs in confined aquifers, while recent and current uses of PFAAs could be the major source of PFAAs in unconfined aquifers, rivers and coastal waters. The risk quotients of PFOA and PFOS in groundwater and rivers were 2-3 orders of magnitude lower than unity, indicating no immediate risks via drinking water consumption.
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http://dx.doi.org/10.1016/j.chemosphere.2016.10.088DOI Listing
February 2017

Effects of Perfluorooctanoic Acid on Metabolic Profiles in Brain and Liver of Mouse Revealed by a High-throughput Targeted Metabolomics Approach.

Sci Rep 2016 Apr 1;6:23963. Epub 2016 Apr 1.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, People's Republic of China.

Perfluorooctanoic acid (PFOA), a perfluoroalkyl acid, can result in hepatotoxicity and neurobehavioral effects in animals. The metabolome, which serves as a connection among transcriptome, proteome and toxic effects, provides pathway-based insights into effects of PFOA. Since understanding of changes in the metabolic profile during hepatotoxicity and neurotoxicity were still incomplete, a high-throughput targeted metabolomics approach (278 metabolites) was used to investigate effects of exposure to PFOA for 28 d on brain and liver of male Balb/c mice. Results of multivariate statistical analysis indicated that PFOA caused alterations in metabolic pathways in exposed individuals. Pathway analysis suggested that PFOA affected metabolism of amino acids, lipids, carbohydrates and energetics. Ten and 18 metabolites were identified as potential unique biomarkers of exposure to PFOA in brain and liver, respectively. In brain, PFOA affected concentrations of neurotransmitters, including serotonin, dopamine, norepinephrine, and glutamate in brain, which provides novel insights into mechanisms of PFOA-induced neurobehavioral effects. In liver, profiles of lipids revealed involvement of β-oxidation and biosynthesis of saturated and unsaturated fatty acids in PFOA-induced hepatotoxicity, while alterations in metabolism of arachidonic acid suggesting potential of PFOA to cause inflammation response in liver. These results provide insight into the mechanism and biomarkers for PFOA-induced effects.
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http://dx.doi.org/10.1038/srep23963DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4817033PMC
April 2016

Distribution of perfluorooctane sulfonate isomers and predicted risk of thyroid hormonal perturbation in drinking water.

Water Res 2015 Jun 11;76:171-80. Epub 2015 Mar 11.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu, PR China. Electronic address:

We documented the distribution of seven perfluorooctane sulfonate (PFOS) isomers in drinking water in Jiangsu Province, China. Compared to the 30% proportion of branched PFOS in technical PFOS, the levels of branched PFOS in drinking water increased to 31.8%-44.6% of total PFOS. Because of previous risk assessment without considering the PFOS isomer profile and the toxicity of individual PFOS isomers, here we performed a new health risk assessment of PFOS for thyroid hormonal perturbation in drinking water with the contribution from individual PFOS isomers. The risk quotients (RQs) of individual PFOS isomers indicated that linear PFOS contributed most to the risk among all the target PFOS isomers (83.0%-90.2% of the total PFOS RQ), and that risk from 6m-PFOS (5.2%-11.9% of the total PFOS RQ) was higher than that from other branched PFOS isomers. We found that the risks associated with PFOS in drinking water would be overestimated by 10.0%-91.7% if contributions from individual PFOS isomers were not considered. The results revealed that the PFOS isomer profile and the toxicity of individual PFOS isomers were important factors in health risk assessment of PFOS and should be considered in the future risk assessments.
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http://dx.doi.org/10.1016/j.watres.2015.02.047DOI Listing
June 2015

Bioassay-directed identification of organic toxicants in water and sediment of Tai Lake, China.

Water Res 2015 Apr 31;73:231-41. Epub 2015 Jan 31.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, People's Republic of China. Electronic address:

The government of China has invested large amounts of money and manpower into revision of water quality standards (WQS). Priority organic pollutants have been screened for WQS establishment using the potential hazard index method, however, some unsuspected chemicals that could cause adverse effects might have been ignored. A large number of chemicals exist in environment and there might be interactions between or among chemicals especially those with the same mode of action. Therefore, a toxicity-directed analysis, based on acute toxicity to Daphnia magna, was conducted for organic extracts of water and sediment from Tai Lake (Ch: Taihu) to determine toxicants responsible for adverse effects. Extracts of five of twelve samples of water and all extracts of sediment were acutely toxic. Based on toxic units, water from location L1 in July and sediments from locations L1 and L4 during several months would be expected to result in some toxicity. Twenty one (21) organophosphorus pesticides, 25 organophosphorus pesticides and 10 pyrethroids were detected in samples, extracts of which caused toxicity to D. magna. Chlorpyrifos and cyfluthrin were identified as predominant pollutants in organic extracts of sediments, accounting for up to 71% and 57% of bioassay-derived toxicity equivalents (BEQs), respectively. Chlorpyrifos was identified as the major contributor to toxicity of organic extracts of surface water, accounting for 71% to 83 % of BEQs. The putative causative agents were confirmed by use of three lines of evidence, including statistical correlation, addition of key pollutants or synergists. Greater attention should be paid to chlorpyrifos and cyfluthrin, neither of which is currently on the list of priority pollutants in China. Bioassay-directed analysis should be added for screening for the presence of priority organic pollutants in environmental media.
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http://dx.doi.org/10.1016/j.watres.2015.01.033DOI Listing
April 2015

Occurrence of organophosphate flame retardants in drinking water from China.

Water Res 2014 May 23;54:53-61. Epub 2014 Jan 23.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China. Electronic address:

Several organophosphate flame retardants (OPFRs) have been identified as known or suspected carcinogens or neurotoxic substances. Given the potential health risks of these compounds, we conducted a comprehensive survey of nine OPFRs in drinking water in China. We found total concentrations of OPFRs in tap water ranging from 85.1 ng/L to 325 ng/L, and tris(2-butoxyethyl) phosphate (TBEP), triphenyl phosphate (TPP), and tris(2-chloroisopropyl) phosphate (TCPP) were the most common components. Similar OPFR concentrations and profiles were observed in water samples processed through six different waterworks in Nanjing, China. However, boiling affected OPFR levels in drinking water by either increasing (e.g., TBEP) or decreasing (e.g., tributyl phosphate, TBP) concentrations depending on the particular compound and the state of the indoor environment. We also found that bottled water contained many of the same major OPFR compounds with concentrations 10-25% lower than those in tap water, although TBEP contamination in bottled water remained a concern. Finally, we concluded that the risk of ingesting OPFRs through drinking water was not a major health concern for either adults or children in China. Nevertheless, drinking water ingestion represents an important exposure pathway for OPFRs.
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http://dx.doi.org/10.1016/j.watres.2014.01.031DOI Listing
May 2014

Occurrence of perfluoroalkyl acids including perfluorooctane sulfonate isomers in Huai River Basin and Taihu Lake in Jiangsu Province, China.

Environ Sci Technol 2013 Jan 4;47(2):710-7. Epub 2013 Jan 4.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China.

The spatial distribution of 10 perfluoroalkyl acids including linear and branched (six monotrifluoromethyl isomers) perfluorooctane sulfonate (PFOS) in surface water was investigated in Huai River Basin and Taihu Lake in Jiangsu Province, China. In the water samples from Huai River Basin, perfluorooctanoic acid (PFOA) and PFOS were the predominant compounds (mean 18 ng/L and 4.7 ng/L, respectively), while in samples from Taihu Lake, PFOA, perfluorohexanoic acid (PFHxA), and PFOS were the predominant compounds (mean 56 ng/L, 19 ng/L, and 15 ng/L, respectively). Branched PFOS (Br-PFOS) isomers accounting for 48.1% to 62.5% of total PFOS were enriched in all samples from Taihu Lake, compared to technical electrochemical fluorination (ECF) PFOS (Br-PFOS ∼30.0%), while the similar phenomena were not found in samples from Huai River Basin (Br-PFOS 29.0-35.0%). Principal component analysis (PCA) on the percentages of the individual isomer showed that the first two components accounted for 78.4% and 15.3% of the overall observed data variance. Samples from Huai River Basin were grouped together with the ECF PFOS standard suggesting the profiles were similar, while samples from Taihu Lake were grouped by themselves, suggesting that isomer profiles in these samples were different from that of Huai River Basin. The obvious difference in isomer profiles probably results from the different environmental behaviors of PFOS isomers and/or unknown sources (PFOS or PFOS precursors).
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http://dx.doi.org/10.1021/es3037803DOI Listing
January 2013